Atmail is a fully-featured email server and Webmail client, allowing users to send and receive email via a Web browser or mobile device. It has full support for
IMAP mailboxes, and an optional email-server mode that uses EXIM as the MTA. Features include a scheduler, MySQL backend support, spell-check, address book, calendar user preferences, multiple accounts, SpamAssassin support, migration scripts from other mail servers, a customizable interface, an attractive AJAX interface, an optional group sharing Calendar/Addressbook, and an Outlook plugin to sync Contacts/Tasks/Calendar data between a Desktop, Mobile, and Webmail client or other email users.

Open-Xchange Server Edition is a multi-tier, small footprint solution that integrates seamlessly into customer’s architectures, enabling smooth start of operation based on services. The Open-Xchange Server Edition supports different Enterprise Linux systems like SUSE Linux Enterprise Server 10, Red Hat Enterprise Linux 5, and Debian Etch. Users are presented with a highly advanced, improved, and intuitive browser based interface that meets all their email, calendaring, tasking, contacts, and document storage requirements. Further integrations like LDAP-support or ADS are possible. It's designed for medium organizations and educational and public administrations that want to have a customizable communication solution.

Airtime lets you take total control of your radio station via the Web with intelligent archive management, powerful search, an easy playlist builder, a simple scheduling calendar, and rock-solid automated playout. Features include fades, cues, playlists, a programme calendar, Icecast, Shoutcast, and Soundcloud integration, DJ and station manager roles, JQuery widgets, Liquidsoap playout, and a record and rebroadcast functionality. Powerful media archive features 'watch' folders to allow stations to magically synchronize files, auto-import files, and has multiple directory support. Users can interact with it through any Web browser. It comes with an 'easy install' package.

Wyrd is a curses front-end for Remind, a powerful
calendar and alarm application. The display
features a scrollable time table suitable for
visualizing your schedule at a glance. Wyrd
integrates with an external editor of your choice
to make editing of reminder files more efficient,
and provides hotkeys to quickly access the most
common Remind options. Other features include
extensive configurability, Mutt-like interface
design, and minimal resource requirements.

tngCalendar is a Web calendar addon to the TNG software for online
genealogy. It adds a convenient view of your family history,
overlaying anniversaries of births, deaths, and marriages on top of
an easy-to-understand calendar. It can be dropped in-place over a
commercial TNG installation, or installed in a parallel directory.

DAViCal is a server implementation of the CalDAV protocol for storing calendaring resources (in iCalendar format) on a remote shared server. An increasing number of calendar clients support the maintenance of shared remote calendars through CalDAV including Mozilla Calendar (Sunbird/Lightning), Evolution, Mulberry, Chandler, and various other closed-source products such as Apple's iCal and iPhone. DAViCal supports basic delegation of read/write access among calendar users, multiple users or clients reading and writing the same calendar entries over time, and scheduling of meetings with free/busy time displayed.

Address Book Server allows you to share your
contacts and calendar events with others connected
to your network or over the Internet. Each
participant synchronizes their contacts with the
server hosted on your own system. Address Book
Server supports the full Address Book and iCal
schema. The server also provides a friendly Web
interface and an iPhone client which let you
access your contact details remotely.

Tine 2.0 is a Web-based groupware solution that focuses on usability and correctness. To achieve these goals, the project uses usability experts and covers most of the code by unit tests. It contains support for contacts, tasks, calendar, email, CRM, VoIP integration, a time tracker, ActiveSync, and a flexible rights management system.